John Quincy Adams (6th President, 1825–1829) is viewed as highly intelligent and accomplished but politically polarizing. He championed infrastructure (roads, canals), founded the Smithsonian, and articulated the Monroe Doctrine. However, domestic initiatives like a national bank failed, and he faced fierce Democratic opposition. He lost re-election in 1828, later serving nine terms in the House. His legacy is mixed: respected statesman, but limited presidential success due to inability to build consensus.